Robert jacob gxlcher



(No Model.)

R. J. GULOHER.

.THBRMO-ELEGTRIG BATTERY.

No. 472,261. Patented Apr; 5, 1892'.-

4| fi r n .65 n

bw 0 5 1 F 2, +2, 171' I 1 UNITED STATES.

PATENT OFFICE.

ROBERT JACOB ei'rLoH'ER, OF BERLIN, GERMANY.

THERMO-ELECTRIC BATTERY SPECIFICATION forming part of LettersApplication filed June 18, 1891.

To all whom it may concern.-

Be itknown that I, ROBERT JACOB GUL HER, engineer, a subject of the Kingof Prussia and German Emperor, residing at Berlin, in the Kingdom ofPrussia and German Empire, have invented certain new and usefulImprovements in 'lhermo- Electric Batteries; and I do hereby declare thefollowing to bea full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and-use the same.

Thisinvention relates to thermo-electric batteries; and it consists inthe novel construction and combination of the parts hereinafter fullydescribed and claimed.

In carrying out this invention the elements which are subjected to aless degree of heat, and which consequently develop less electromotiveforce, are made of less resistance than the elements which are subjectedto a greater degree of heat, and the difference in the resistances ofthe elements is made substantially proportional to the ditferences intheir temperatures. This change in resistance may Kbe accomplished bymaking the elements of larger size to lessen their resistance, or by,changing the metal or alloy of which they are composed.

In the accompanying drawings, Figure 1 shows a vertical section of athermo-electric battery constructed according to the present invention.Fig. 2 is a sectional plan view of a single row of elements. Figs. 3 and4 are detail plan views of modifications of two of the elements.

a a is the heating-chamber, around which are arranged-the wheel-shapedrows of elements 1) 1) 12 &c., which are placed one above the other. Thepoints of connection 0 c of the separate elements themselves form theinner wall of the heating-chamber. The separate elements, as also therows of elements, are insulated from each otherin a suitable manner bymeans of layers'e of material that is atthe same time a bad conductor ofheat, such. as a mixture of fossil-meal and asbestus. The cooling of thesoldered parts 01 d is efiected by copper bands f f, soldered thereto,which are connected by wires to hoops of insulat- Patent No. 472,261,dated April 5,1892.

Serial No. 396,782. (No model.)

ing material g g, such as ebonite,-paraifined wood, &c. The proportionbetween the internal resistance and the electro-motive force is renderedconstant in each row ot' elements by making the'separate elements ofequal size only so far as the temperature of the heatingchamber is aboutat the same height, such as from Z) to N. From the point where thetemperature begins to decrease the sections of the elements are made togradually increase, bein for this purpose increased in height, while theother dimensions remain the same, such as from b to b".

The heating-cha1nber a a is heated by means of a Bunsen burner lothollow cylindrical form, which imparts to the chamber a constant hightemperature over a tolerably-extended surface, such as from b to b". Itwill be readily understood that the thermoelectric pile could also beotherwise heated, such as by a petroleum-burner or by a coke-fi re. The

rows of elements rest in the present instance upon a suitable standfined together with the burnert It upon a base-plate 0. On the rings 9of thetop .row of elements is placed a conical hood it hot sheet-iron,with a central outlet, which can be connected in any convenient mannerwith a chimney in order to expose the cooling-bands f f to a strongcurrent of air. The hood h h is provided with lugs, through which andthrough corresponding lugs on the bottom-stand pass screw-bolts forsecuring the parts firmly together.

Fig. 2 showsa sectional plan of a single row of elements. 0 c are theconnecting-pieces or intermediate contacts to be heated, which are madeof a good conductorof heat, such as copper. on one side thereof thepositive electrodes p p of sheet-nickel are brazed, while the negativeelectrodes 1) b of an alloys'uch as antimony and zinc-are cast' intohollows of the said contacts. The separate elements, which are placedclosely side by side at their connecting parts 0 c, are insulated fromeach other by thin strips of mica q q. The remain 5 ing free'spacebetween the elements is filled with a bad conductor of heat e e, withwhich the elements are also covered at top and bottom. There are twocopper cooling-bands ff connected to each element, whereby an effectivecooling of the outer soldered points (I d is produced. 9 is the ring ofvulcanite or other material, to which the outer ends of thecooltug-bands are attached.

The drawings show all the elements connected in series. They may,however, accordingto circumstances, be all or partly connected inparallel. The mode of connecting the elements in the one row, however,determincs the mode of connection of the other rows in the same pile.The rows themselves must always be connected in series. Several rows ofelements could be combined together In groups of equal electro motiveforce, and these groups may then be connected in parallel.

Figs. 3 and 4 show two of the new elements with the extendedintermediate contacts 0 o. b b are the negative electrodes ofeasily-fusible metal, which are cast around the dovetailed plugs c ofthe intermediate contacts. The positive electrodes consist, for example,of. strips of sheet-nickel p p, and they are connected with the ends ofthe intermediate contactseither by brazing them on, as at Fig. 3, or bycastingthem on, as at Fig. 4. Only the ends 0 0, connected to thepositive electrodes, are directly subjected to the temperature of thesource of heat, While the ends 0', connected to the negative electrodes,only transmit such heat to the latter as is conducted from c to 0'through the intermediate contact. Fol-this purpose the elements may be,for example, arranged in the same manner as shown at Fig. 2, the entirefree space both between the extended intermediate contacts andalsob'etween the electrodes being filled withan insulating bad conductorof heat. By suitably proportioning the extended'cintermediate contact aconsiderable difference of temperature may be maintained between the twopoints 0 and 0', so that if, for example, the positive electrode p has atemperature of, say, 500 centigrade and above the negative electrode at0' only receives a heat'of, say, 300 centigrade, which temperature isbelow the melting-point of the alloy employed.

What l claim is 1. In a thermo-electric battery, the combination, with asource of heat, of elements having different internal resistances, saidelements being arranged in agraduated series, the elements of lessinternal resistance being arranged at a distance from the source of heatso that the resistance of each element is substantially proportional tothe temperature to which it is subjected, and all the said elements ofdifferent internal resistances being connected in series, substantiallyas and for the purpose set forth.

2. In a thermoelectric battery, the combination, with a source of heat,of elements of different sizes, said elements being arranged in agraduated series, the larger elements, which have less internalresistance, being arranged at a distance from the said source of heat sothat the resistance of each element is substantially proportional to thetemperature to which it is subjected, and all the said elements ofdifferent sizes being connected in series, substantially as and for thepurpose set forth.

3. In a thermo-electric battery, the combination, with a central sourceof heat, of elements arranged in rows around the said source of heat,the said rows being arranged in a graduated series, the elements in therows which are more remote from the sourceof heat beingof less internalresistance, substantially in proportion to the lower temperature towhich they are subjected, and the said rows of elements having difierentresistances being connected in series, substantially as and for thepurpose set forth.

4. A thermoelectric element consisting of a negative electrode offusible metal, a positive electrode of refractory inetal and anintermediate metallic contact-piece having its opposite ends secured tothe said electrodes, said contact-piece being adapted to be heated onlyat that end of it to which the said positive electrode isconnected andproportioned so that a considerable difference in the temperature of itsends is constantly maintained, substantially and for the purpose setforth.

In testimony whereof I affix my signature in presence of two witnesses.

ROBERT moon GULCHER.

\Vitnesses:

MARC M. ROTTEN, SIEGFRIED ITAMBURGER.

